1. Field of the Invention
The field of the invention is that of ratchet wrenches.
2. Description of the Prior Art
Ratchet wrenches which are held in the hand and are driven by a motor are commercially known in the art. Such wrenches typically embody a handle part and a head with an extending shaft adapted to have mounted on it a socket which can engage a nut for turning it. Drive means are provided whereby the ratchet wrench will cause the drive shaft to move angularly in steps of predetermined amount.
Typically, there is a member which is mounted to be oscillated by the drive motor and a ratchet pawl is positioned to cooperate with the oscillating member, the ratchet member causing the angular step movement to be transmitted to the shaft.
The head of the wrench typically, is relatively small and the above-described parts are incorporated in the head. Ordinarily, a cylindrical member or rotor is provided which carries the shaft which is moved angularly. For proper operation, means are provided to apply friction to the circular member or rotor. Known commercial devices as described have been subject to certain deficiencies. Among these were that the parts as described within the head were put together with members requiring particularly that the circular member or rotor have a number of holes in it which cause it to be weakened with the result that it would frequently break under the stress of operation. Also, the means provided for applying friction to this member were relatively complicated and required providing the rotor with holes which weakened it.